Checking The Resolution Change Ic Movement - Acer AL502 Service Manual

8. Checking the resolution change IC movement

Is there +3.3V supply on I300 pin 17, 21, 57, 77, 79, 97, 102, 117, 137, 154, 156, 157 and 65.
OK
Is 12MHz clock input to I300 pin 3 at
OK
Is +5.0V supplied to I300 pin 2 at
OK
Failure point
I300 failure
Print wire broke between I302 pin 6
Page 10
NG
Proceed "Checking the DC/DC converter circuit" section.
TTL level?
Is 12MHz clock output from X300
NG
at TTL level?
OK NG
Failure point
Print wire broke between X301 and
I300 pin 3.
High level?
Check the output of 5.0V "H" pulse
NG
from I302 pin 6.
NG
OK
Failure point
and I300 pin 2.
Failure point
X300 failure
Is 5.0V supplied to I302 pin 7?
NG
OK
Failure point
I302 failure
A L C502
Failure point
1) FB319 open
2) Power source
Trou bl e Sh ooti ng